Testing Money and Numbers: A 35-Point Checklist of Where It All Breaks
0.1 + 0.2 ≠ 0.3 — and that's just the start. Money and numbers are a minefield: float error, rounding, locales, currencies, boundary values. A first-person take: why money isn't stored in float, rounding and splitting an amount, locale formatting, currency decimal places, user input, and the business logic of discounts and taxes. With a flat checklist.